1. Field of the Invention
The invention relates to a link chain formed of a sequence of individual, consecutive chain links linked with one another. More particularly, the invention relates to a link chain having an arrangement which prevents or minimizes misalignment of the link chain.
2. The Prior Art
Link chains consist of a plurality of individual chain links linked with one another. In the case of link chains for industrial applications, such as, for example, a hoist chain for use in underground coal mining, the individual chain links are subjected to extremely high tensile stress.
A link chain demonstrates its maximum ability to withstand tensile stress when the individual chain links are disposed one after the other in an intended manner such that the inside portions of two facing arcs of two consecutive chain links rest against one another. The rated ability of a link chain to withstand stress regularly presupposes that the chain links of the link chain that is subject to the tensile stress are disposed, relative to one another, in the intended manner described above.
However, if individual chain links are not located in their intended arrangement, so that a second chain link linked into a first chain link borders on the arc of the first chain link not with the inside of its arc, but with the inside of its shank, for example, this chain link cannot withstand the rated stress. This chain link therefore forms a weak point of the link chain. When the chain is loose and not under tensile stress, the individual chain links can change position relative to one another, and remain in this arrangement relative to one another when the link chain is put under stress again. The link chain has then become misaligned. The misaligned chain links not only represent a weakening of the chain with regard to its ability to withstand stress, but also present a risk that the misaligned segments of the link chain will damage drive units for moving the chain, or will themselves be destroyed. For this reason, in underground coal mining, the link chains used for scoop bucket conveyors are typically pre-tensed and checked while the chain is hanging, before stress is put on them.